The present invention relates to an anti-dementia agent, and more particularly to an anti-dementia agent comprising an antiamnestically effective amount of a benzylpyridine derivative.
It is disclosed in Japanese Published Examined Patent Application No. 32629/85 that benzylpyridine derivatives related to the present invention possess an antidepressive and antiinflammatory activity. However, it is unknown that these compounds have an antiamnestic activity and therefore, their use as an anti-dementia agent is unknown.
With the prolongation of the average span of life in recent years, the number of people with senile dementia has been rapidly increasing. Such people are afflicted with memory loss often accompanied with wandering, unclean and dangerous behavior or symptoms such as personality change and allophasis.
To treat senile dementia, a variety of drugs have been administered to patients in the clinical field.
Representative examples include cerebral metabolism activators such as idebenone, calcium hopatenate, and amantadine hydrochloride; cerebrovasodilators such as vinpocetine and dihydroergotoxin mesylate, (described in "Senile Dementia and Anti-dementia Agents--Aiming at Developing New Anti-dementia Agents", edited by Kenji Kosaka and Takeshi Ishii, Japan Society for Science and Technology (1987)); and oxiracetam, an experimental treatment.
Use of these drugs alleviates subjective symptoms relating to emotion. However, the main symptoms of senile dementia involving deterioration of intellectual functions such as decrease in impressibility and disorientation, are not necessarily alleviated by these treatments. Therefore, it is desirable to develop new drugs which alleviate symptoms of memory deterioration such as impressibility and orientation. To this end, it has been found that certain benzylpyridine derivatives have a strong antiamnestic activity and are thus useful as anti-dementia agents.